Jacking mechanisms

ABSTRACT

Jacking mechanisms are used in connection with supporting legs for an offshore platform or barge which supports oil well drilling apparatus or servicing apparatus in the open sea. The present jacking mechanism combines the action of hydraulic cylinders with flexible devices, such as cables, for transmitting movement to the supporting legs relative to the offshore platform or barge in effecting substantially continuous but step-by-step rectilineur movement of the supporting legs. A pair of hydraulic cylinders or jacks are located symmetrically with respect to each of two or more chords of a leg or with respect to the leg, and act respectively for movement of a traveling head or heads that may be keyed step-by-step to the chord or chords of the leg. A substantially continuous jacking operation is accomplished by the engaged and disengaged pin ends of the respective cylinders together. The chord of each leg is fabricated so as to utilize a heavy section, properly braced for the key connection with a jacking unit.

United States Patent 1191 Sutton Apr. 16, 1974 JACKING MECHANISMS [76] Inventor: John R. Sutton, PO. Box 32,

Beaumont, Tex. 77704 22] Filed: Apr. 14, 1972 [2]] Appl. No.: 244,038

[52] US. Cl. 254/105, 61/465 [51] Int. Cl B66f 1/00, E02d 21/00 [58] Field of Search 254/93 R, 105, 109; 61/465 [56] References Cited UNITED STATES PATENTS 2,016,575 /1935 Nenec et a1 254/109 2,715,013 8/1955 Slick 254/106 2,947,148 8/1960 Young 61/465 2,992,812 7/1961 Rasnussen et a]. 254/107 Primary Examiner-Othell M. Simpson Attorney, Agent, or Firm-Burns, Doane, Swecker & Mathis [5 7] ABSTRACT Jacking mechanisms are used in connection with supporting legs for an offshore platform or barge which supports oil well drilling apparatus or servicing apparatus inthe open sea. The present jacking mechanism combines the action of hydraulic cylinders with flexible devices, such as cables, for transmitting movement to the supporting legs relative to the offshore platform or barge in effecting substantially continuous but stepby-step rectilineur movement of the supporting legs. A pair of hydraulic cylinders or jacks are located symmetrically with respect to each of two or more chords of a leg or with respect to the leg, and act respectively for movement of a traveling head or heads that may be keyed step-by-step to the chord or chords of the leg. A substantially continuous jacking operation is accomplished by the engaged and disengaged pin ends of the respective cylinders together.

The chord of each leg is fabricated so as to utilize a heavy section, properly braced for the key connection with a jacking unit.

18 Claims Drawing Figures 'u lll v r 0 o 0 .93 o o L a) O "#95' O O O O PATENTEUAPR 16 I974 8 F u a lu E E H S ff//////// ll //l mgmamrmmm I 3804.369 SHEU 5 UPS BACKGROUND OF DISCLOSURE This invention relates to improvements in jacking mechanisms adapted to be used particularly for off shore platforms or barges for effecting relative vertical movement thereof with respect to supporting legs.

An offshore platform or barge is usually employed for supporting drilling or servicing mechanism in the open sea. It is desirable that the platform or barge be elevated above the surface of the sea so as to be relieved of the action of waves on the body of the platform or barge. Thus, it is customary to mount the platform or barge on a pluarlity of supporting legs which are lowered to the surface of the earth beneath the sea and upon which the platform or barge can be raised to an elevated position for effecting the necessary drilling or servicing operation. .Iacking machanism is used on the platform or barge for effecting the relative vertical movement between the latter and the legs, a separate jacking mechanism for each leg, but all of the jacking mechanisms operating in concert or individually, as desired. Due to the unevenness of the surface beneath the sea, it is often necessary to move the legs to different degrees in order to provide secure support for the several legs and to maintain the platform or barge in a level position.

Many different forms of jacking mechanisms have been proposed heretofore, one of which is set forth in my prior US. Pat. No. 3,245,658, dated Apr. 12, I966, which is referred to merely as an example of the types of mechanisms proposed for use for these purposes.

One object of this invention is to simplify and improve the construction of jacking mechanisms so as to effect relative rectilinear motion between the legs and the platform or barge that will be effective to support the latter. which may be manufactured and operated at low cost.

Another object of the invention is to provide a stepby-step action to effect relative rectilinear movement between the leg and the platform or barge in a mechanism that will be relatively foolproof, effective in action and will assure of proper operation when needed.

Still another object of the invention is to provide for use of hydraulic mechanism combined with flexible devices such as cables in step-by-step manner so as to effect positive rectilinear movement of the leg with respect to the platform or barge.

These objects may be accomplished, according to one embodiment of the invention, by means ofa jacking assembly for each leg comprising a jacking unit for one or more chords of the leg. Each jacking unit, according to this invention, utilizes hydraulic cylinder action for effecting movement of a traveling head or beam that may be keyed into a chord of the leg and which head is interconnected by flexible devices, such as cables or chains, with the platform or barge so that, upon alternate action of the pair of cylinder devices, the leg will be moved stepby-Step with respect to the platform or barge.

The leg structure includes a chord which has a heavy section capable of supporting the weight of traveling movement and is effectively braced so as to utilize a second section of appreciably lighter structure, thus reducing the cost of the leg structure.

V chrohydraulic jacking apparatus in. relation to a BRIEF DESCRIPTION OF THE DRAWINGS Certain embodiments of the invention are illustrated in the accompanying drawings, in which:

FIG. 1 is a diagrammatic side elevation of an offshore platform or barge supported by a. plurality of legs and to be moved thereon to an elevated position with respect to the body of water;

FIG. 2 is a diagrammatic plan view of one of the legs;

FIG. 3 is a horizontal section through a portion of one of the legs substantially on the line 3-3 in FIG. 4;

FIG. 4 is a side elevation thereof, with a portion of the barge in section;

FIG. 5 is a side elevation of one of the synchrohydraulic jacking units shown substantially on the line 5-5 in FIG. 3;

FIG. 6 is a detail cross section through one form of cylinder connection;

FIG. 7 is a horizontal section therethrough on the line 77 in FIG. 6;

FIG. 8 is a disassembled elevation, with a part in perspective, showing the assembly of parts of the cylinder connection;

FIG. 9 is a detail side elevation, showing a modification of cylinder connection;

FIG. 10 is a front elevation of a modified form of synportion of the barge, such as a jack house;

FIG. 1 1 is a horizontal section through a leg assembly showing the relation of the leg chords to the leg well;

FIG. Ila is a detail horizontal section showing a modified leg well and chord assembly;

FIG. 12 is a plan view, partly in section, of the holding pin block;

FIG. 13 is a side elevation, partly in section, of the jack head with wire lines and chain attachments thereto; and

FIG. 14 is a side elevation of a traveling block with wire lines and chain attachments thereto.

DETAILED DESCRIPTION OF DISCLOSURE The invention is illustrated in connection with a suitable platform or barge capable of floating on the sur' face of a body of water and illustrated generally at 1 in FIG. 1. This platform or barge 1 has ajack house 1 on each of a plurality of locations on the deck thereof, the roof structure of which is indicated at 2, while the deck of the platform or barge is shown at 3.

The platform or barge 1 is provided with a plurality of upright legs 4 extending through openings 5 (FIG. 3) in the deck or decks thereof. A well 51 (FIG. 11) may be used to enclose the opening in the platform or barge, extending downwardly from the deck 3 below the jack house 1' through the deck or decks of the barge or platform. The well 51 should be sufficiently large for sliding movement of the leg therethrough. The leg usually has a round tank footing 4', and this footing can be drawn up into the well 51 when the Ieg is raised for floating the platform or barge.

The barge is floated to the drilling or service site, after which the legs are lowered into bearing relation with the bottom of the body of water, as illustrated, for example, in FIG. 1. When the legs are lowered so as to rest securely upon the earths surface beneath the body of water, the jacking mechanism provided for the respective legs and which is used for the lowering of the legs, is continued to be operated so as to raise the barge or platform to an elevated position where it will not be subjected to the action of the waves or motion of the water, but will be stably supported.

An opening is provided in the top of the jack house 1' which usually corresponds with the cross section of the leg, acting as a hearing at this point. Thus the top opening may be triangular or square, for example, and of a size to have a sliding fit with the correspondingly shaped leg.

A separate jacking mechanism is provided for each leg. The several jacking mechanisms for the plurality of legs may be operated independently or in concert, but usually the legs will need to be moved to different extents to accommodate irregularities in the earths surface beneath the body of water. The leg may be fabricated of triangular, square or of other desired shape in cross section and character, and the jacking mechanism for each leg may comprise one or more jacking units as found desirable, usually arranged symmetrically with respect thereto. With a triangular leg, a jacking unit is preferably used for each chord, whereas with a square leg or a large diameter cylindrical leg, jacking units would be provided at each of the diagonally opposite two chords or on opposite sides of the cylindrical leg.

In FIGS. 2 to 4, I have illustrated a leg as comprising a plurality of chords 6 secured in spaced relation by bracing members 7 in an assembly that is shown to be triangular in form although other suitable or desired shapes may be used for the purpose. A jacking unit, generally indicated at 8, is provided for one or more of the chords 6, as may be needed to effect proper rectilinear movement of the leg. In FIG. 2, I have shown a jacking unit 8 for each chord 6 of a triangular leg, but the jacking unit may be omitted from one or more of these chords, if desired, as indicated, for example, in FIG. 4, or for a square leg as explained above.

In this embodiment of the invention, each of the chords 6 is cylindrical in shape and the bracing members 7 extend radially thereof so as to form a triangular assembly as mentioned. Additional diagonal bracing may be used, if desired, as illustrated at 9 in FIG. 4, and extending from one of the chords 6 to the next adjacent chord on a corresponding side of the leg. Also tie braces between the bracing members 7 are often used.

Each of the chords 6 may also be braced by radial and longitudinal gusset plates 10 and 11, respectively, which are slotted and interfitted, and preferably welded to the inner surfaces of the chords. The gusset plates 10 are shown in FIG. 3 as extending through slots in the bracing member 7 and may also be welded to the latter. This forms a secure and effective structure of low cost that will have the stability and strength necessary for supporting the barge or platform.

Each of the chords 6 that is adapted for operation and connection with one of the jacking units is preferably constructed of a relatively heavy section in the area thereof that has a key connection with the jacking unit, as illustrated in FIG. 3.

In this form of the invention, the chord 6 is shown as formed of semi-circular sections 12 and 13 which are welded or secured together at the adjoining edges thereof so as to form a smooth exterior cylindrical surface. The section 12, however, is appreciably thicker in wall section than the section 13, the latter having the bracing members 7 and 9 connected thereto where the same strength is not required.

The opposite edges of the thicker section 12 are connected together by a bridge plate 14, as shown in FIG. 3, which bridge plate extends axially along the length of the chord 6 and in bridging relation across the edges of the semi-cylindrical section 12 to which its opposite edges are welded. Thus, the bridge plate 14 aids in maintaining the stability of the chord under different conditions of stress. Additional radial bridge plates 14' may be used if desired.

As an example, the semi-cylindrical section 13 and the bridge plate 14 may be made of rolled plate, with a wall thickness of l-Vz inches, while the semicylindrical outside chord wall 12 may be formed from a spun tube with 6 inch wall thickness. This gives the added strength needed in the areas of leg connections. The welding may be a straight line weldment to the inside rolled plate wall, making a complete rounded leg chord of fixed outside diameter having the desired strength.

The section 12 of the chord 6 is provided with openings or holes 15 spaced at intervals along the length thereof, as shown in FIGS. 4 and 5, to be used in step by-step movement of the leg with respect to the platform or barge. These openings are spaced apart lengthwise and also, in this embodiment of the invention, are in two series at from each other, as will be apparent from FIG. 3. In the example described, the spin cast pipe may be made in the order of 17 feet; then cut in half for the outside section of the chord, and with the pin holes 15 cut in bias section 4 feet or 5 feet apart on center.

Disposed in cooperative relation with each series of openings or holes 15 on one or more of the chords 6 is a jacking device which comprises a pair of jack units, generally indicated at 16 or 17, respectively, and shown particularly in FIGS. 3 to 5.

Each of the jack units 16 and 17 comprises a movable jack head 18 within which an engaging pin 19 is mounted for reciprocating movement into and out of the respective openings 15 at the corresponding side of the chord section 12. The engaging pin 19 is reciprocated by action of a double acting fluid cylinder 19 connected therewith, which may be either air or hydraulic according to the available fluid. Suitable controls (not shown) are provided so that one of the pins 19 will be engaged in an opening 15 at one segment of the section12 while the other pin will be withdrawn therefrom. This is the relation illustrated in FIG. 3 wherein the jack unit 16 has its pin 19 engaged and the corresponding pin 19 of the jack unit 17 is shown as retracted. These act alternately in engaged relation to advance the leg step-by-step.

The head 18 of each unit 16 and 17 is mounted on a hydraulic cylinder 20, one end of which, shown as the piston end, is connected at 21 with the movable head 18. The opposite end of the cylinder 20 is mounted in a suitable swivel upon a suitable fixed part of the platform or barge as, for example, on the deck 3, at the bot tom of the jack house 1.

In the form of the invention illustrated in FIGS. 5 to 8, the cylinder end of the hydraulic cylinder 20 has a depending or axially extending pin 22 provided with a head 23 mounted in a supporting block 24 secured in suitable position on the platform or barge such, for example, as on the deck 3.

The block 24 has a recess 26 therein for the head 23, as illustrated in FIG. 7, with a slot 25 opening to one side of the block 24 to accommodate the pin 22. Bearing collars 27 and 28 are interposed above and below the head 23; and each of these bearing collars 27 and 28 is split to be assembled in sections in the recess 26. On opposite sides of the recess 26, the block 24 has overhanging flanges 29 and the block also has a bottom plate 30.

A cover 31 fits between the flanges 29 and over the bottom plate 30 complementary to the head 23 and the bearing collars 27 and 28 so as to confine these in place. A cavity 26 in the facing side of the cover 31 receives an edge of the head 23. A recess 31' conforms to the periphery of the pin 22 between the flanges 29, closing the open side of the recess between the latter. This cover 31 has a series of sleeves 32 spaced around the periphery thereof through which bolts 33 are inserted and threaded into the bottom flange plate 30, thereby to secure the cover 31 fixedly in position in secure relation to the head 24 while yet permitting the swiveling movement of the lower end 23 of the cylinder with respect to the head and the mounting thereof on the barge or platform.

Upon operation of the cylinder 20 of either or both of the jack units 16 and 17, the head 18thereof will be moved lengthwise of the chord 6 of the leg, alternately in opposite directions. The movement of the heads 18 of the respective jack units may be guided by back-up frame members 34 (FIG. 3) extending lengthwise of the leg, being anchored at opposite ends to secure portion of the barge or platform, such as the roof 2 of the jack house 1' and the deck 3.

Mounted upon the head 18 of each cylinder 20 is a traveling wire line sheave 35 journaled at 36 on bearing plates 37 extending upwardly from the head 18 and mounted thereon. The sheave 35 is shown as tapered and is freely journaled for turning movement. It may be provided, if desired, with peripheral grooves 38 (FIG. 3) therein to receive wire cables 39 that are anchored at their outer ends to tie-down bars 40 mounted in fixed positions as, for example, on the desk 3 of the platform or barge.

The outer ends of the wire lines 39 being anchored at 40, these lines extend in loops over the sheaves 35 of the respective jack units 16 and 17 and have their intermediate portions extending around a sheave 41 journaled on a bearingsupport 42 mounted in suitable bearing blocks 43 (see FIG. 5) supported in a fixed position upon the platform or barge.

If it be desired, the supporting block 24 for each cylinder 20 may be supported upon a mounting head 44 supported upon the platform or barge as, for example,

on the deck 3. Also mounted on the head 44 is a holding pin assembly 45 fluid actuated, in the manner described above with'respect to the pin 19. The holding pin will be engaged in one of the openings for locking the leg in a fixed position with respect to the barge or platform as for example, when it is to be maintained in position for an extended period of time.

In lieu of the swivel connection of each cylinder with respect to the barge or platform, the cylinder may be pivotally supported thereon, as shown in FIG. 9. For example, the cylinder 20 has a depending plate 46 at the closed end of the cylinder which is mounted between a pair of brackets 47 by a pivot pin 48. In this form, the cylinder can swing back and forth with respect to the chord of the leg although retained in a circurnferential position with respect thereto.

In lowering a leg with respect to the platform or barge. the engaging pin 19 of one unit. as 16, is projected by the cylinder 19' into an aligned opening 15. The engaging pin 19 of the other unit, as 17, is withdrawn from its aligned opening 15. The cylinder 20 of the unit 17 is then actuated to move the head 18 upward with respect to the leg chord 6, until at the end of its stroke the pin 19 of this unit 1.7 is aligned with one of the openings 15, when the cylinder 19 of the unit 17 is actuated to project the pin 19 into the aligned openmg.

This relative upward movement of the block 18 of the unit 17 will cause the looped end portions of thelines 39 extending over the sheave 35 thereof to travel upward and thereby force downward the opposite end portions of the lines 39 of the unit 16. In this action the unit 16 is moving the leg downward relative to the platform or barge. Then the pin 19 of the unit 17 is projected into an aligned opening 15 while the pin 19 of the unit 16 is retracted. Then the unit 16 is actuated as described. These continue alternately to effect movement of the leg, until it reaches the: desired position relative to the earth or with respect to the platform or barge.

Ifjacking units are provided for several chords of one leg, these may be actuated in concert. Likewise all of the legs may be actuated individually or together. The hydraulic systems used for controlling thejacking units are not illustrated in detail because conventional hydraulic valving systems may be used.

OPERATION The cylinders 20 are preferably double acting hydraulic cylinders that are provided with suitable controls which are well known in the art. These cylinders will effect rectilinear movement of the engaging pins 19 so as to align these with the respective openings 15 in the chord member 6. The fluid cylinders 19' are likewise controlled so as to project and retract the pins 19 at desired times for engaging or disengaging the openings l5.

These cylinders 20 maintain the lines 39 under tension at all times. The lines are anchored at their opposite ends and travel over the sheave 41 intermediate their ends in response to alternate travel of the respective cylinders 20. The cylinders of the jack units 16 and 17 normally travel in opposite directions, one of which moves upward when the other one is moved downward by the action of the lines 39.

Thus the lines assist the hydraulic pressure in lifting the barge or platform, thereby enabling the jack units to move in loaded position on each stroke of the cylinders, both when engaged with the leg and when disengaged. This permits alternate and instant engagement of the jack unit 16, for example, when it has completed its assist lift supporting the jack unit 17 when it is engaging the leg chord 6. This alternating synchronized operation affords continuous jacking action without the pause required to extend the jacks for alternate strokes which has been required heretofore with other jacking systems. Most jacking systems have required the stroke of the cylinder to be extended before taking a lifting stroke which requires a long pause in the operation. Extending a rod to its maximum length takes almost as much time as the completion of a loaded stroke.

The action described above may be reversed for lifting the leg with respect to the barge or platform, in the alternate step-by-step action of engaging and releasing the respective pins 19 in the key openings 15.

In this invention, two hydraulic cylinders are used for each jack unit and these are operated in opposite, alternating, synchronized strokes both of which are under load at all times. Through the use of flexible devices, such as wire lines operatively connected with each jack unit, the unit disengaged from the leg assists the jack unit engaged with the leg while it is being returned for its next stroke. The opposed jack unit, in turn, assists, by its capacity, in a push direction, effecting a continuous jacking operation and spreading the load carried between the wire lines and the connected jacking units. The wire lines are held in tension at all times by the synchronized control system operating the two hydraulic cylinders.

MODIFIED FORM OF DISCLOSURE The leg chords shown in FIG. 11 are identical with those described above and illustrated at 6. These are the chords that are adapted for key engagement with the jacking mechanism. When jacking units are to be connected with chord at diametrically opposite sides of a square leg, both of these would be constructed as described in connection with the chord 6. The intermedi' ate chords shown at 6' in FIG. 11 would not require the heavy sections as illustrated at 12.

The leg chord assembly is shown in FIG. 11 as enclosed within a leg well 51 which surrounds the entire assembly. The leg well 51 is mounted in a fixed position in the platform or barge below the jack house 1' which encloses the jacking mechanism. The well 51 provides for sliding movement of the leg therethrough as it is moved up or down relative to the platform or barge. Guides are shown at 52 on the inner wall of the well 51 to receive therein the respective chords of the leg assembly for movement relative thereto.

These guides 52 are shown in FIG. 11 as gusset plates having notches 53 receiving the chords. However, if the arc of the well plate 51 passes through the center of the chord, the guides may be formed as channels in the plate 51, as indicated at 52 in FIG. 11a.

The well 51 extends through the barge from deck to bottom and houses the cylindrical footing on the bottom of the leg when the leg is elevated for mobile condition. The structure of the jack units fits close to the leg on the deck inside the jack house and must be built to supprt the barge on the legs as well as the jacking forces. The jack house is a part of this structural frame which may extend through the depth of the barge adjacent the leg well wall 51 to the top of the jack house, and, as an example, the top may be 30 feet above the deck. The leg is not enclosed by a well wall from the deck to the top of the jack house except for the jack house frame. The top of the jack house forms a bearing support for the very tall leg for such barge.

I have shown in FIGS. to 14 a modified form of jacking unit which utilizes the principles described above without requiring as large wire lines and sheaves and wherein the cylinders are in axial alignment rather than side by side.

Referring to FIG. 10, the jacking unit is mounted in secure relation to the platform or barge as, for example, in the jack house 1 upon the deck 3. A portion of the frame structure of the jack house is shown at 54,

with a support 55 extending transversely thereof and securely mounted in fixed position on the platform or barge. This support 55 serves as a mounting for one of the hydraulic cylinders, as hereinafter explained.

Upper and lower hydraulic cylinders are illustrated at 56 and 57, respectively, disposed in axial alignment, one above the other, beside and parallel to one of the leg chords 6. These are double-acting hydraulic cylinders, powered in opposite directions, as explained above in connection with the cylinders 20.

The upper cylinder 56 is mounted on the support member 55 as, for example, by a ball and socket mounting, generally indicated at 58, which may be constructed in the manner described above in connection with FIGS. 6 to 8.

The piston end of the cylinder 56 is connected at 59 to the under side of a lifting beam 60 that extends transversely across the piston end of the cylinder 56 and is secured thereto so as to be raised and lowered by the outward and inward movements of the piston rod thereof.

The lower hydraulic cylinder 57 is mounted in a fixed position on the platform or barge as, for example, on the deck 3. The cylinder end of the piston 57 may also be mounted in a ball and socket joint, generally indicated at 61, as described above in connection with FIGS. 6 to 8 for obtaining proper alignment of the piston.

The upper end of the cylinder 57 which includes the piston rod thereof is shown as secured at 62 to a lower lifting beam 63, which beam is fixedly secured on the piston end of the cylinder to be raised and lowered by the expansion and contraction thereof.

Two sets of lifting chains 64, such as sprocket chains, are connected with the upper lifting beam 60. These sprocket chains 64 are connected at 65 with the upper lifting beam 60 and extend upwardly therefrom over sprockets 66 journaled at 67 in the jack house roof frame structure, thence downwardly to traveling blocks, generally indicated at 68.

An assembly of wire lines 69 is connected at one end to each of the traveling blocks 68 and extends downwardly therefrom to one end portion of the lower lifting beam 63, being fixedly secured to the latter.

A second set of chains, such as standard 4-sprocket chains, is indicated at 70, extending downwardly from each opposite end portion of the lower lifting beam 63, being connected thereto at 71 and being substantially in axial alignment with the wire lines 69, as shown in FIG. 10. The sprocket chains extend downward and around sprocket wheels 72, journaled in a fixed position in the platform or barge as, for example, on the barge deck 3, and thence upward to traveling blocks 73. Wire lines 74 are connected at one end with each of the traveling blocks 73 and extend upward therefrom to the opposite ends of the upper lifting beam 60 to which these wire lines 74 are secured, as indicated at 75.

FIG. 13 shows in detail the connections of the chains 70 and wire line cables 69 with the lower lifting beam 63. The chains 70 have the respective ends thereof attached to swivels 76 mounted on the pivot pin 71 forming the pivotal connection with the lower lifting beam 63. This allows freedom of raising and lowering movements of the lifting beam and thereby rectilinear movement of the chains. At the same time, the wire line cables 69 are attached by sockets 77 secured in the upper portion of the lifting beam so as to move rectilinearly with the raising and lower movements of the beam.

In FIG. 14 I have shown on somewhat smaller scale a connection between the wire line cables 69 and the chains 64 by means of the traveling block 68. This is described in connection with the traveling block 68 but the same type of connection in reverse position applies also to the traveling block 73. The chains 64 have swivel connections at 68, with a pin 79 mounted on the traveling block to form secure swivel connections of the chains thereto substantially in axial alignment with the wire line cables 69. The latter are connected through sockets 80 with the underside of the traveling block 68 substantially in the manner shown in FIG. 14.

In this form of the invention a sprocket and roller chain are used for joining the two cylinders to augment each other. Each of the lifting beams 60 and 63'is provided with a locking pin, indicated generally at 81 and 82, respectively, for alternate engagement in the pin holes 15 of the chord 6.

A locking pin is indicated also at 83 mounted within the frame support 55 for selective locking of the chord and leg in a set position. The construction and operation of these locking pins is substantially the same as has been described above in connection with the engaging pin 19.

One of the pins 81 and 82 is engaged while the other is disengaged, enabling the disengaged pin block to pull in tension on the engaged pin block when it is ordinarily being extended unloaded for its next stroke. In other words, the return stroke of one of the cylinders acts in tension through the cables and chains to augment the movement on the other lifting beam so that by proper operation of the engaged pins, both cylinders act to effect movement of the leg in either direction in substantially a continuous action.

The alternate pin is ready for engagement when the lifting stroke is completed by the engaged pin. This saves the lapse of time that has been required heretofore where the hydraulic cylinder acted only in one di' rection and there was a pause in operation on the return stroke. This synchrmhydraulic dual action will keep the lifting operation in a continuous movement, thereby eliminating the dead stops and delay causing the barge to become static. In this synchro-hydraulic system, as shown in the drawings, the load remains dynamic as it is shifted from the engaging pin 81 to the engaging pin 82, and alternately, for each lifting stroke.

This same condition works in both directions, both in pushing the leg down until it meets bottom resistance, at which time the jacking units push the barge up on the leg, thereby elevating it above the water. The barge may be loweredback to the water surface by reversing the steps and the legs raised from the bottom by continued jacking in reverse sequence. The same capacity of jacking is accomplished in either direction and the same continuous jacking takes place as in lowering the legsand raising the barge.

The system has effective safety features. The roller chains has positive traction with the sprockets and these sprockets may be effectively braked in conventional manner for additional safety in the event of cylinder or pressure failure. One cylinder is always holding the other in this'system, thereby increasing the effectiveness of safety in the jacking operation.

The wire lines are used for straight line pull according to this embodiment of the invention, thereby reduc- LII ing the amount of roller chain to the area engaging the sprockets which effects maximum economy of design.

By having the respective cylinders in vertical alignment, it is not necessary to use more than one row of pin holes 15 in the leg chord 6 for engagement by the pins 81 and 82 in the respective lifting beamsThis reduces the cost of cutting one line of pin holes in the leg chord and also avoids weakening of the chord by reason of additional holes.

Moreover, the present form of the invention hasIan additional holding pin 83 in the jack house frame 55 that can be used at times and would be sufficient to hold the barge leg in a set position.

Legs that penetrate the bottom independently will stop penetration at various depths. This may require an adjustable holding pin block to lock off at various positions of each of the pin holes in a. leg. Such a holding pin block may be provided beneath the support for the jacking unit, as indicated generally in FIGS. 10 and 12, where the block is shown at 84 having a locking pin 85 for selective engagement in the pin holes 15.

The block may be supported on a standard screw jack 86 which extends downward to a lower portion of the platform or barge such as the next lower deck for raising and lowering the pin 85 into proper alignment with one of the pin holes 15.

A pair of threaded posts 87 extends downward from the deck 3 which are threaded on two sides each, with flattened portions between the threaded sides, and extend through a locking sleeve 88 so as to follow freedom of sliding movement of the block 84 lengthwise of the threaded posts 87 by adjusting of the screw jack 86. When the pin 85 is aligned with one of the pin holes 15, the adjusting sleeves 88 can be turned to shift the block 84 into binding relation by engaging the threads of the posts 87. This will hold the pin 85 engaged in the pin hole 15 on the chord 6 and thereby prevent relative shifting of the chord and the leg with respect to the platform or barge.

A continuous jacking operation is accomplished by tying the engaged and disengaged pin blocks together. This makes each stroke "of the respective cylinders a load lifting stroke. It also more than doubles the lifting capacity of each cylinder as compared with a single stroke system wherein the cylinder lifts with power from the rod end in a tension stroke.

It also more than doubles the lifting capacity of each cylinder as compared with a single stroke system wherein the cylinder lifts with power from the rod end in a tension stroke. The capacity of the cylinder is materially increased in the push stroke, under compression, due to the volumeof fluid lost in the rod end stroke by the size of the rod.

According to this invention, one cylinder is always pulling while the other is pushing. Thus, a 500 ton cylinder in pulling stroke combined with its 1,000 ton capacity in pushing stroke would give a jacking capacity of at least L200 tons if 20 percent. be deducted forloss of efficiency. This is assuming that their capacities are tied together and without overloading the wire lines and sprocket chains. The chains and cables, according to the modified form of disclosure, would have approximately 800 ton capacity, combined.

This invention uses fewer hydraulic cylinders than has been required with other systems employed heretofore. For example, this invention would use four or six hydraulic cylinders, depending on the capacity of each,

working in unison. Prior systems have used at least 6 cylinders per leg working in tension, with single acting strokes, with resulting slower action.

The jacking system according to this invention is attached to the platform or barge more effectively than in prior systems. Not only are the engaging pins attached to the barge, but the cylinders are also attached to the barge, and the pulleys or sprockets are also attached. This splits the load between these points, whereas most other systems carry the entire load on the cylinder pin doing the lifting. Moreover, the invention uses two cylinders ties together, doubling the safety factor.

While the invention is illustrated and described in certain embodiments, it is recognized that variations and changes may be made therein without departing from the invention set forth in the claims.

I claim:

1. Jacking apparatus for effecting relative vertical movement between an upright column leg and a platform, said jacking apparatus comprising a head, means for connecting the head step-by-step with the leg, an upright power device fixed at one end and connected at the opposite end with the head, guide means on the head, and one or more flexible lines extending over the guide means and having power means operatively connected therewith and acting on one or more of the flexible lines for moving the head and the leg connected therewith.

2. Jacking apparatus according to claim 1, wherein the power means is a second fluid power device.

3. Jacking apparatus for effective relative vertical movement between an upright column leg and a platform, said jacking apparatus comprising relatively movable heads beside the column leg, means for connecting the heads with the leg, power devices fixed at one end and connected at the opposite end with the respective heads, guide means on each of the heads, separate guide means in a fixed position spaced from the power devices, and one or more flexible lines extending over the guide means on the heads and over the separate guide means for actuation in response to movement of the respective power devices to move the leg with respect to the platform.

4. Jacking apparatus according to claim 3, wherein the one or more flexible lines are fixed at opposite ends thereof and extend over the guide means on the heads intermediate said fixed points.

5. Jacking apparatus according to claim 3, wherein the one or more flexible lines have intermediate portions extending over the separate guide means and thence over the guide means on the heads to fixed points.

6. Jacking apparatus according to claim 3, wherein the connecting means between each head and the leg acts step-by-step in effecting relative movement therebetween.

7. Jacking apparatus for effecting relative vertical movement between an upright column leg and a platform, said jacking apparatus comprising relatively movable heads beside the column leg, said column having a chord with rows of openings therein aligned with the respective heads, pins carried by the heads in positions for selective engagement in the openings, upright power devices fixed at one end and connected at the opposite end with the respective heads, and means including one or more flexible lines extending in guided relation with the respective heads for transmitting movement of one of the heads in one direction to effect movement of the other head in the opposite direction.

8. Jacking apparatus according to claim 7, including guide sheaves mounted on the respective heads and having the lines extending in loops thereover.

9. Jacking apparatus according to claim 8, wherein the lines have opposite ends anchored and have intermediate portions looped about a fixed guide member.

10. Jacking apparatus according to claim 7, wherein the power devices are upright cylinders, and means forming a swiveled connection of one end of each cylinder.

ll. Jacking apparatus for effecting relative vertical movement between an upright column leg and a platform, said jacking apparatuscomprising upper and lower lifting beams beside the column leg, said column including chord having a row of openings therein, pins carried by the beams in positions for selective engagement in the openings, upright power devices fixed at one end and connected at the opposite end with the respective heads, and means including one or more flexible lines extended in guided relation from one of the beams to the other for transmitting movement of either of the beams in one direction to effect movement of the other beam in the opposite direction.

12. Jacking apparatus according to claim 11, wherein the upright power devices are mounted substantially in axial alignment and act to move the respective beams lengthwise relative thereto.

13. Jacking apparatus according to claim 11, wherein the movement transmitting means includes a flexible cable and a flexible chain connected together end to end, and gearing means in guided relation with the chain.

14. Jacking apparatus according to claim 11, wherein the movement transmitting means includes flexible cables and sprocket chains connected end to end for conjoint rectilinear movement and extending from one of the beams to the other, and guide sprockets for the chains having the chains looped therearound.

l5. Jacking apparatus for effecting relative vertical movement of an upright column leg and a platform or barge, said jacking apparatus comprising means forming spaced points of engagement along the length of the leg, a plurality of engaging means for alternate engagement with said spaced points of engagement, a separate power device for each engaging means for applying motion alternately in opposite directions lengthwise of the leg to each of the respective engaging means, and means for interconnecting the power devices for transmitting movement of each to the other in both directions and for augmenting the power of the other when operating in the opposite direction.

16. A jacking apparatus according to claim 15, wherein each engaging means includes a thrust beam, with means for attachment to the leg, a single power device for each thrust beam, and the interconnecting means is separate from the power device.

17. Jacking apparatus according to claim 15, wherein the power devices are fluid cylinders disposed parallel with a line parallel to each other.

18. Jacking apparatus according to claim 15, wherein the points of engagement are openings formed in the leg in a row or rows spaced along the length thereof, and the engaging means are pins disposed for selective engagement with the openings. 

1. Jacking apparatus for effecting relative vertical movement between an upright column leg and a platform, said jacking apparatus comprising a head, means for connecting the head stepby-step with the leg, an upright power device fixed at one end and connected at the opposite end with the head, guide means on the head, and one or more flexible lines extending over the guide means and having power means operatively connected therewith and acting on one or more of the flexible lines for moving the head and the leg connected therewith.
 2. Jacking apparatus according to claim 1, wherein the power means is a second fluid power device.
 3. Jacking apparatus for effective relative vertical movement between an upright column leg and a platform, said jacking apparatus comprising relatively movable heads beside the column leg, means for connecting the heads with the leg, power devices fixed at one end and connected at the opposite end with the respective heads, guide means on each of the heads, separate guide means in a fixed position spaced from the power devices, and one or more flexible lines extending over the guide means on the heads and over the separate guide means for actuation in response to movement of the respective power devices to move the leg with respect to the platform.
 4. Jacking apparatus according to claim 3, wherein the one or more flexible lines are fixed at opposite ends thereof and extend over the guide means on the heads intermediate said fixed points.
 5. Jacking apparatus according to claim 3, wherein the one or more flexible lines have intermediate portions extending over the separate guide means and thence over the guide means on the heads to fixed points.
 6. Jacking apparatus according to claim 3, wherein the connecting means between each head and the leg acts step-by-step in effecting relative movement therebetween.
 7. Jacking apparatus for effecting relative vertical movement between an upright column leg and a platform, said jacking apparatus comprising relatively movable heads beside the column leg, said column having a chord with rows of openings therein aligned with the respective heads, pins carried by the heads in positions for selective engagement in the openings, upright power devices fixed at one end and connected at the opposite end with the respective heads, and means including one or more flexible lines extending in guided relation with the respective heads for transmitting movement of one of the heads in one direction to effect movement of the other head in the opposite direction.
 8. Jacking apparatus according to claim 7, including guide sheaves mounted on the respective heads and having the lines extending in loops thereover.
 9. Jacking apparatus according to claim 8, wherein the lines have opposite ends anchored and have intermediate portions looped about a fixed guide member.
 10. Jacking apparatus according to claim 7, wherein the power devices are upright cylinders, and means forming a swiveled connection of one end of each cylinder.
 11. Jacking apparatus for effecting relative vertical movement between an upright column leg and a platform, said jacking apparatus comprising upper and lower lifting beams beside the column leg, said column including chord having a row of openings therein, pins carried by the beams in positions for selective engagement in the openings, upright power devices fixed at one end and connected at the opposite end with the respective heads, and means including one or more flexible lines extended in guided relation from one of the beams to the other for transmitting movement of either of the beams in one direction to effect movement of the other beam in the opposite direction.
 12. Jacking apparatus according to claim 11, wherein the upright power devices are mounted substantially in axial alignment and act to move the respective beams lengthwise relative thereto.
 13. Jacking apparatus according to claim 11, wherein the movement transmitting means includes a flexible cable and a flexible chain connected together end to end, and gearing means in guided relation with the chain.
 14. Jacking apparatus according to claim 11, wherein the movement transmitting means includes flexible cables and sprocket chains connected end to end for conjoint rectilinear movement and extending from one of the beams to the other, and guide sprockets for the chains having the chains looped therearound.
 15. Jacking apparatus for effecting relative vertical movement of an upright column leg and a platform or barge, said jacking apparatus comprising means forming spaced points of engagement along the length of the leg, a plurality of engaging means for alternate engagement with said spaced points of engagement, a separate power device for each engaging means for applying motion alternately in opposite directions lengthwise of the leg to each of the respective engaging means, and means for interconnecting the power devices for transmitting movement of each to the other in both directions and for augmenting the power of the other when operating in the opposite direction.
 16. A jacking apparatus according to claim 15, wherein each engaging means includes a thrust beam, with means for attachment to the leg, a single power device for each thrust beam, and the interconnecting means is separate from the power device.
 17. Jacking apparatus according to claim 15, wherein the power devices are fluid cylinders disposed parallel with a line parallel to each other.
 18. Jacking apparatus according to claim 15, wherein the points of engagement are openings formed in the leg in a row or rows spaced along the length thereof, and the engaging means are pins disposed for selective engagement with the openings. 